In a unnamed high fantasy setting, humans and other sentient races have set their eyes on the New World, a separate continent from the populated Old World. The New World is an untamed wilderness where many power monsters roam, and researchers have been drawn to study these creatures and their habitat. Several ocean-bound Fleets have been sent already to establish working bases, safe from monsters, and operations are led by the Research Commission.

The Hunter along with his assistant the Handler are part of the Fifth Fleet, which has been summoned by the Research Commission to provide more support on the New World. As they near the New World, the gigantic monster, Zorah Magdaros, appears and devastates the ships and tears a path through the New World, however, most including the Hunter and Handler make it safely to shore and to Astera, the main base for the Research Commission there. Once acclamated, the Commission`s Commander tells the Fifth Fleet that they are curious as to why the Zorah Magdaros has been drawn to the New World, an event they know that happens every ten years, and gives the Hunters orders to help them set up various camps in new areas revealed by the Zorah Magdaros` passing, clearing out any hostile monsters they may find.